Question: Who was Frederick William I of Prussia's child and what is the date of their birth?
Paraphrase: Who used to be Frederick William I of Prussia's child and what is the date of their birth?
SPARQL (Wikidata): SELECT ?value1 ?obj WHERE { wd:Q105013 p:P40 ?s . ?s ps:P40 ?obj . ?s pq:P569 ?value1 . }